I have a Fastfire II, currently mounted on a Ruger Mini-14. It is made well, and very compact, and able to withstand considerable recoil. It has a simple on-off switch and an automatic light sensor. It also turns off automatically if you cover it with a provided hood.
The downside is that it is difficult to adjust. You can get it "on the paper" with a bore sight, but there are no calibrated markings for the final adjustments. It is by trial and error.
The best way to adjust it is with the firearm in a solid vice, centered on the bullseye, then moving the red dot until it covers the point of impact. Like any reflex sight, you can look through it with a telescope without affecting the point of aim. You must loosen both locking screws to adjust either windage or elevation.
Another "con" is that you have to dismount the sight to replace the battery, which is located on the open underside of the device.
The Fastfire III allows you to change the battery from the top, and has level settings in addition to the automatic sensor. It is slightly larger than the model II, and a little more expensive, still in the $200 range.
It wouldn't be hard to modify a standard holster to fit with the Fastfire in place. The 2 MOA dot is more than adequate for hunting at handgun range (less than 80 yards).
